When two people marry, each exchanges the potential for having a satisfying sexual relationship with others for his/her spouse agreeing to do everything he/she can to meet the sexual needs of the spouse. If either party defaults on Part B, he/she loses the moral right to complain if the other stops honoring Part A.
Each partner agrees to sexual exclusivity, not to a life of sexual activity granted or withheld at the whim of the other, and usually spiced with emotional manipulation.
A husband or wife should not have to "woo" his or her spouse. Though doing so might very well be part of the "meeting the sexual needs of the other" agreed to.
IOW, when you marry, you lose the moral right to turn the sexual tap on and off when you feel like it.
1 Cor. 7: "2 But since there is so much immorality, each man should have his own wife, and each woman her own husband. 3 The husband should fulfill his marital duty to his wife, and likewise the wife to her husband. 4 The wife's body does not belong to her alone but also to her husband. In the same way, the husband's body does not belong to him alone but also to his wife."
A lot of people don't like this idea. That's fine. They just shouldn't get married, agreeing to a contract they have no intention of living up to.
BTW, there are situations where one party loses the ability to engage in some or all types of sexual activity for physical reasons. That's tragic, but it doesn't release the spouse from his/her obligation to be sexually faithful. The spouse agrees to do whatever he/she can to meet sexual needs.
Well said!